This invention relates to a protective decorative cap for covering tile lug nut and bolt or stud for attaching a wheel rim to a car, truck, bus, or the like. A variety of such protective, decorative caps have been developed. A common problem encountered is to ensure that the cover will remain on the lug nut on the vehicle during use. For example, in Applicant's U.S. Pat. No. 5,082,409, the cover is retained by means of a plurality of clips within the shell cavity.
U.S. Pat. No. 4,824,305, McCauly, relies on a plastic insert within the decorative shell for permanently mounting the insert within the shell and an annular-longitudinal portion of the insert as internal threads for mating engagement with the thread of the stud.
U.S. Pat. No. 4,890,967, Rosenbaum, utilizes a resilient, compressible retainer having legs which align with the flats of a bolt head or nut over which a generally cylindrical cap is applied.
U.S. Pat. No. 4,582,462, Thiel utilizes at least two axial profile webs on the internal face of the casing arranged to engage and hold the cap on the nut.
U.S. Pat. No. 4,576,533, Chartier utilizes an annular channel formed in the inner wall of the cap for receiving a snap fit engagement with a lower circumferential flange of a particular type of fastener head.
U.S. Pat. No. 5,163,739, Standlake, uses a wheel cover having ,a plurality of tubular extensions for attaching the wheel cover to the lug nuts of the wheel.
French Patent No. 2386-722 utilizes two diametrically opposite tongues to retain the cap on the bolt.